Economizer



7- w. H. ARMACOST ET AL 2,069,515

ECONOMIZER I Filed July 5, 1935 INVENTOR W/L awe flkh mcosr.

BY Ja 4 h. 55/1/65 T/QKEM ATT'ORNEY Patented Feb. 2, 1937 UNITED STATES PATENT OFFICE ECONOMIZER Application July 5, 1935, Serial No. 29,926

14 Claims.

This invention relates to heat transfer apparatus and particularly to means for supporting the tubular elements thereof through which a fluid is circulated in heat exchanging relation with another fluid flowing over the surfaces of the tubes. The invention will be described by way of illustration as embodied in an economizer having a plurality of tubes through which boilerfeed water is circulated to absorb heat from the boiler gases.

One feature of the invention resides in supporting the tubes in such manner as to prevent sagging thereof because of their length and weight.

A second feature resides in relieving the tube sheets and headers for the tubes of substantially all the strain usually imposed thereon by the weight of the tubes.

Another feature resides in supporting the tubes so that they are free to expand or contract when subjected to temperature changes.

A fourth feature resides in providing for easy removal of some of the tubes for replacement or repairs without disturbing the supporting means 25 for other tubes. 7

Other features and advantages of the invention will become apparent upon consideration of the following detailed description and the appended claims when read in conjunction with the ac- 30 companying drawing in which:

Figure 1 is a vertical sectional view, partly broken away, of an economizer embodying the present invention;

Figure 2 is a fragmentary sectional view on the 35 line 2-2 in Figure 1;

Figure 3 isan enlarged side elevation of end portions of a pair of adjacent tubes;

Figure 4 is an enlarged scale sectional view on the line 4--4 in Figure 1 illustrating a bifurcated,

i{0 sinuous heat absorbing element and showing the manner of supporting the superposed tubes of each bifurcation or branch thereof in accordance with the invention; and

Figure 5 is a sectional view on the line 5-5 in 45 Figure 4.

Referring to the drawing, the economizer comprises an open-ended casing l0 which contains a plurality of sinuous tubular heat absorbing elements l2, one of which appears in Fig. 1. The

5 elements l2 are disposed in side by side relation, Fig. 2, and are exposed to boiler gases that flow through the casing for heating feed water or other fluid circulated through the elements be-' tween the inlet and outlet headers l4, l6, respec- 55 tively. Each element comprises a number of superposed tubes I 8 interconnected by return bends to form a sinuous and continuous tubular element.

As is best shown in Figures 3 and 4, suspension means 3| are provided on the upper and lower 5 surfaces of each tube, the suspension means on adjacent superposed tubes being interconnected by bolts 32 or other fastening devices so that each tube is suspended from the tube immediately above. The topmost tube 21 has rods 33 at- 10 tached to the suspension means 3| on its upper surface for supporting the entire element from beams 34 that extend transversely of the row of elements.

In the illustrated embodiment of the invention, 5 the suspension means consist of longitudinal fins located diametrically on each tube and preferably extending along substantially the entire length of its upper and lower surfaces between the return bends that connect with the tubes above and below. Except between certain pairs of tubes, as will be described presently, the lower fin on one of a pair of immediately superposed tubes partially overlaps the upper fin of the other tube of the pair and is connected thereto at a number of points by bolts 32.

The elements l2 illustrated in the drawing consist of several sections 2|, 22, 23, 24 and the return bends 20 connecting the lower tube 25 of one section to the upper tube 26 of the adjacent 30 section are disconnectable from these tubes. Likewise, the end tubes 21 of each element are disconnectable from the elbows 28 or other piping connecting the element with the headers l4,

l6. With this arrangement any of the sections 2| to 24 with its several constituent tubes may be removed for repairs or replacement when those tubes of the section which extend through the tube sheet 30 are disconnected from the related return bends 20 and header connections 28. 40

It is desirable to permit removal of some of the sections of an element l2 without leaving the remainder of the element without support unless jacked up or being similarly held in place. Furthermore the usual close spacing of the elements !2 would interfere with easy access tothe bolts 32 for removing them from connecting relation between the lower fin on a tube 25 of one section and the upper fin on a tube 26 of'the next lower section. Accordingly, the lowermost tubes 25 of one section and the uppermost tubes 26 of the section immediately below it in an element are interconnected by a bar 36 rather than by bolts passing through their opposed fins. As

shown in Figure 4 the tubes 25 and 26 are proof the other elements l2.

one or more intermediately located bars may be provided if desired. The bars 36 extend transversely of the row of elements [2 and are similarly connected between corresponding pairs of tubes With :this arrangement, a section such as 22 of any element I2 may be removed and notwithstanding this the other sections 23, 24 therebelow remain supported through the intermediary of the bars 33 from theupper'sections 2|, 22 of adjacent elements. 'In'removing a section, such as 22, of an element, the door at the front of the casing is opened and the return bends 20 connecting the section 22 to the section 2| above and the 'section'23 below are disconnected. Upon-removal of the panel at the rear of the casing, a section 22 may be withdrawn by sliding it endwise, and the section thus disengaged from the bars 36 and removed entirely from the casing.

The ends of each bar 36 extend into a recess or pocket 40 in the side walls of the casing 10.

Clearance is'provided between the top and bottom of the bar end and the opposed faces of the recessto permit vertical movements of the elementsnpon expansion or contraction. The thicknesses of bar 36 and. recess 40 are so related thatthe side faces of the bar are located closely adjacent the opposed side walls 4| (Fig. 5) of recess '40 to hold the bar, positioned for proper engagement with the interlock parts 31 on the tubes 25, 26 and to prevent disconnection of bar 36 and these tubes in the event that the latter move in the direction of their longitudinal axes, because of expansion or contraction for example.

As illustrated herein, the several sections 2| to 24 of the tubular elements 12 are bifurcated or formed of two sinuous tubes disposed in side by side relation .andinterconnected for parallel fluid flow between end portions that connect with the elbows 28 or return bends 20'; one branch .or bifurcation of a section of an element'is shown at the right of Fig. 4 and'the other bifurcation at the left of said figure. Further, as illustrated in Fig. 4, the component tubes of each bifurcation of an element l2 are also offset or staggered with respect to each other. Thus, each element l2 occupies a wider portion of the gas pass than would be the case if the superposed component tubes of the two branches ofa section of an element were vertically aligned. Thimbles 43 disposed on the bolts 32 between the overlapping fins on the component tubes of each bifurcation maintain said component tubes in their staggered relation. Similar thimbles 44 pcsitioned on each bolt maintain the respective horizontally aligned tubes of the two branches in the sectioncspaced and further rigidify and strengthen the bifurcated element. A single bolt may beutilized for interconnecting horizontally aligned tubes in, the respective bifurcations as .well as for connecting the lower fin on any tube 10f eachbi'furcation to the d pper fin on the next lower tubeof the same bifurcation.

It should be'noted thatsince the-elements are supported from above they may move vertically if temperature conditions cause them to expand or contract. Further, the headers and the usual tube sheets are relieved of the aggregate weight of the tubes which is considerable when many elements l2 with long tubes are used. This obviates many troublesome sources of water and gas leakage. Moreover, because the tubes are suspended from each other a greater. number of elements may be installed in a given space since it is not necessary to provide hangers extending vertically between the elements. Elements I?! with long tubes may be utilized inasmuch as sagging of the tubes because of their weight is eliminated. In addition to providing for support of the tubes the fins also increase the effective heat absorbing surfaces of the tubes.

In'some forms of'heattransfer apparatus it is often desirable to provide baffles to form lanes for directing the flow of the heating or cooling fluid over thetubes. By securing'opposed and overlapping fins 3| on certain tubes in contact with each other such lanes may be formed between the elements at desired locations without providing special baffling extending between the tubes. 7 What We claim is: g

1. In heat transfer apparatus having a plurality of fluid circulating'tubes disposed one above the other; suspension means on the upper and lower surfaces of each tube and extending longitudinally thereof for the greater portion of its length; means securing the suspension means on the upper surface of each tube at a plurality of points with the suspension means on the lower surface of the tube thereabove; and means supporting the uppermost tube, whereby each tube below the uppermost one is suspended from the tube above and supported by the uppermost tube.

2. In heat transfer apparatus having a plurality of fluid circulating tubes disposed one above the other; suspension means on the upper and lower surfaces-of each tube and extending longitudinally thereof for the greater portion of its length; means securing the suspension means on the upper surface of each tube at a plurality of points with the suspension means on the lower surface of the tube thereabove; and supporting means connected to the suspension means on the upper surface, of the topmost tube, whereby each of the other tubes is suspended from the tube thereabove and supported from the topmost tube.

3. In heat transfer apparatus; a plurality of sinuous fluid circulating elements disposed in side by side relation and each comprising a plurality 4. In a heat transfer apparatus as recited in claim 1 but wherein immediately adjacent superposed tubes are offset horizontally with respect to each other; means associated with the interconnected suspension means of the tubes for maintaining the offset relation thereof.

-5. In heat transfer apparatus having a plurality of tubes aligned in a numberof horizontal and vertical rows with the tubes of adjacent rows disposed'in staggered relation; suspension means-se- 7 cured to the upper and lower surfaces of said tubes; and means connecting the suspension means on the lower surfaces of said tubes in any horizontal row with the suspension means on the upper surfaces of tubes in the adjacent lower row for supporting the tubes of any horizontal row from the tubes of a row thereabove.

6. In heat transfer apparatus having a plurality of tubes aligned in a number of horizontal and vertical rows with the tubes of adjacent rows disposed in staggered relation; suspension means secured to the upper and lower surfaces of said tubes; means connecting the suspension means on the lower surfaces of said tubes in any horizontal row with the suspension means on the upper surfaces of tubes in the adjacent lower row for supporting the tubes of any horizontal row from the tubes of a row thereabove; and means associated with said suspension means for maintaining the staggered relation of said tubes.

7. In a heat transfer apparatus having a plurality of superposed tubes; suspension means secured to the upper and lower surfaces of said tubes between the ends thereof, the suspension means on the lower surface of each tube partially overlapping the suspension means on the up vper surface of the tube therebelow; and means securing the said overlapping suspension means to each other for supporting each tube from the tube thereabove.

8. In a heat transfer apparatus having a plurality of superposed tubes; fins on the upper and lower surfaces of said tubes between the ends thereof, the upper fin on each tube partially overlapping the lower fin on the tube thereabove along the entire lengths of said fins; and means securing said overlapping fins to each other at a number of points for suspending each from the tube thereabove.

9. In heat transfer apparatus having sinuous fluid-circulating elements each comprising a plurality of interconnected tubes disposed one above the other; longitudinal fins on the upper and lower surfaces of said tubes; means securing the lower fin on each tube to the upper fin on the tube therebelow for suspending all the tubes of said element below the topmost one from the latter; and supporting means connected to the topmost tube.

10. The combination recited in claim 9, wherein the superposed tubes of each element are disposed in staggered relation and the fins on each tube partially overlap the lower fin of the tube above and the upper fin of the tube below; means disposed between and fixedly connecting overlapping fin portions for suspending each tube from the tube above and for maintaining the offset relation of said tubes; and means connected to the topmost tube of each element for supporting its weight and that of all the other tubes suspended therefrom.

11. In a heat transfer device; a sinuous fluidcirculating element comprising a tube bifurcated between its ends with the bifurcations of each of the superposed sinuous courses thereof disposed in side by side relation and staggered with respect to those of adjacent courses; fins secured to the upper and lower surfaces of each tube bifurcation; and means securing the upper fin on each bifurcation to the lower fins on the bifurcations thereabove for supporting the tube bifurcations of the successive sinuous courses from those thereabove and for rigidifying the element to strengthen it against distortion of the staggered tube-bifurcations forming the successive courses thereof.

12. In heat transfer apparatus; a plurality of sinuous fluid circulating elements disposed in side by side relation and each divided into an upper section and at least one lower section each of which sections comprises a plurality of superposed tubes interconnected by fixed return bends with detachable return bends interconnecting the sections of the respective elements; suspension means on the bottom surface of the lowermost tube in the upper section and on the top surface of the uppermost tube in the lower section of each element; and a member extending transversely of the elements between the lowermost tube of the upper section and the uppermost tube of the lower section of each element and detachably engaged with said suspension means on said tubes for supporting the lower section of each element from the upper section thereof and also from. the upper sections of adjacent elements, whereby upon disconnection of the detachable return bend between the upper and lower sections of any element the said upper section may be removed while the lower section of said element remains supported from the upper sections of adjacent elements through the intermediary of said transverse member engaging with the suspension means on the bottom surfaces of the lowermost tubes in the upper sections of said adjacent elements and with the suspension means on the top surface of the uppermost tube of the lower section of the element from which the upper section has been removed.

13. In heat transfer apparatus; a plurality of sinuous fluid circulating elements disposed in side by side relation and each having a plurality of superimposed sections which comprise a number of superposed tubes; detachable return bends connecting the lowest tube of one section of an element to the uppermost tube of the section immediately below; fixed return bends interconnecting the other, intermediate, tubes of each section; suspension means on the bottom surface of the lowermost tube and on the top surface of the uppermost tube of each section; and members extending transversely of said elements between corresponding sections thereof and disengageably connected with the suspension means on the bottom surfaces of the lowermost tubes in corresponding sections of all elements and with the suspension means on the top surfaces of the uppermost tubes in the immediately lower sections of all elements for supporting the lower sections of each element from the section thereabove, whereby any section abo e the lowermost one in any element may be disconnected from the section thereabove and upon removal of the disconnected section from supporting relation with the transverse member to which its lowermost tube was connected, the sections of said element below the removed section remain supported from the upper sections of adjacent elements through the intermediary of said transverse member.

14. In heat transfer apparatus as recited in claim 12, wherein said suspension means are provided at intervals along the tubes; means preeluding movement of said transverse member longitudinally of said elements for maintaining it positioned to retain engagement with such suspension means on the tubes.

WILBUR H. ARMACOST. JOHN H. SENGSTAKEN. 

